Lubricating system for sewing machines



Dec. 19, 1961 TORU MATSUBARA 3,013,532

LUBRICATING SYSTEM FOR SEWING MACHINES Filed March 16, 1959 3 Sheets-Sheet 1 FIG. I 10 INVENTOR.

ToRu M pcrsummz A Dec. 19, 1961 TORU MATSUBARA LUBRICATING SYSTEM FOR SEWING MACHINES Filed March 16, 1959 3 Sheets-Sheet 2 JNVEN TOR. TORU M ATSU BARR m z-wom ana Dec. 19, 1961 TORU MATSUBARA 3,013,632

LUBRICATING SYSTEM FOR SEWING MACHINES Filed March 16, 1959 3 Sheets-Sheet 3 FIG-4 /2 20 I Z! /0 INVENTOR. Tow-u MATS UBB'RA MMM United States Patent 3,013,632 LUBRICATING SYSTEM FOR SEWING MACHINES Toru Matsubara, Tokyo, Japan, assignor to Tokyo Juki I Kogyo Kabushiki Kaisha, Tokyo, Japan Filed Mar. 16, 1959, Ser. No. 799,669 Claims priority, application Japan Mar. 22, 1958 4 Claims. (Cl. 184-6) This invention relates to a lubricating system for sewing machines, particularly to withdrawing excess oil from a sump chamber located in the jaw portion of a sewing machine.

An object of this invention is to provide a lubricating system to be employed in conjunction with an existing sewing machine head lubrication distributing system whereby excess oil is withdrawn by means of siphoning from a sump chamber located in the jaw portion of the sewing machine to a reservoir located below the sump chamber.

Another object of this invention is to provide a lubrieating system to be employed in conjunction with an existing sewing machine head lubrication distributing system whereby excess oil is siphoned from a sump chamber located in the jaw portion of the sewing machine to a reservoir located below the sump chamber when the sewing machine is in operation.

A further object of the invention is to provide a lubricating system to be employed in conjunction with an existing sewing machine head lubrication distributing system whereby a partial withdrawal of excess oil from a sump chamber located in the jaw portion of the sewing machine effected by a decrease of pressure caused by the flow of oil in said distributing system when the sewing machine is in operation is continued by siphoning action when the sewing machine is not in operation, thereby effecting a withdrawal of the excess oil from a sump chamber located in the jaw portion of the sewing machine to a reservoir located below the sump chamber, and whereby the siphoning action may withdraw all the excess oil in the sump.

A still further object of this invention is to provide a lubricating system to be employed in conjunction with an existing sewing machine head lubrication distributing system, said lubricating system employing a tube that connects a sump chamber with a second point on said lubrication distributing system, said tube having a check valve which in a closed position when the machine is being operated thereby prevents the passage of oil from said lubrication distributing system to said sump chamber and in an open position when the machine is not being operated thereby permits the withdrawal of excess oil by a siphoning action from said sump chamber located in the jaw portion of the sewing machine through said tube and other means to a reservoir located below the sump.

An important feature of this invention is as a supplementary system to an existing sewing machine head lubrication distributing system, which consists of an oil pump, a sump chamber, a reservoir located below the sump chamber, and related piping, said supplementary system comprising a tube for withdrawal of excess oil from said sump in conjunction with said machine head lubrication distributing system, said tube having means that prevent "ice 2 the passage of oil from said lubrication distributing systemto said sump, said means comprising an extension of said tube into said lubrication distributing system or in the alternative, rather than said extension, a check valve at a point where said tube is connected to said lubrication distributing system, said lubrication distributing system having outlets, all of said outlets being located below said sump chamber so that said tube and said related piping may act as a means for withdrawing excess oil'from said sump by siphoning when the machine is not in operation.

The present invention may be more clearly understood when the description below is compared with the following drawings.

In the drawings:

FIG. 1 is a vertical section of a sewing machine showing the present invention in conjunction with a sewing machine head lubrication distributing system;

FIG. 2 is an enlarged front View of a three-way oil junction showing the internal parts thereof in phantom lines;

FIG. 3 is an enlarged front view of the present invention in conjunction with a sewing'machine head lubrication distributing system with portions of this related piping cut away and showing theinternal parts of the threeway oil junction as well as ball-type check valves in phantom lines;

FIG. 4 is a vertical section of a'sewing machine showing a second embodiment of the present invention in conjunction with a sewing machine head lubrication distributing system and showing spring-type check valves; and

FIG. 5 is a view similar to FIG. 3, but showing the second embodiment of the present invention and also showing the ball-type check valves in phantom lines.

Referring to FIGS. 1-3, the machine head 10 has with in its cavity a three-way oil junction 1 which joins three pipe members by means of nuts 24, 27 and 28. These pipes are joined as follows: First, the oil feed pipe 4 which originates at the oil pump 3 proximate to the oil level in the reservoir 2; second, the tube 7 through which excess oil is withdrawn from the sump chamber 6 located in the jaw portion 5 of the sewing machine head; third, the return line 8 which passes downward to the vicinity of the lower shaft 14 and the reservoir 2. In thethreeway junction 1, said oil feed pipe 4 is directly joined to said retinn line 3 by means of a joint pipe 21. Said pipes in combination comprise an oilpiping system P. As may be seen in FIGS. l-3, tip 32 of nozzle 18 in turn connected to tube 7 extends into said joint pipe 21,said extension'is thereby positioned proximate to the flow of oil from said oil pump 3 through said oil feed pipe4, said joint pipe 21 and said return line 8, and said flow of oil causes a reduction of pressure in said nozzle 18 resulting in a siphoning action in tube 7. Said siphoning action in tube 7 thereby eiiects a withdrawal of oil from said sum-p chamber 6 located in the jaw portion 5 of the sewing machine head. A branch oil feeder 9 allows oil to flow to the bearing metal 15 of the lower shaft 14. Also, bracket 20 is a fixing member for the three-way junction 1.

FIGS. 4 and 5 show a second embodiment of the present invention wherein the tube 7 is directly connected to joint pipe 21 through a check valve 12. Said check valve 12 operates as follows. When the machine is operating and oil is flowing from said oil feed pipe 4 to said return line 8, the check valve is in a closed position and prevents the flowing oil from passing into the sump 6. When the machine is not operating and the oil is flowing in the return line 8 creating a negative pressure, the check valve is in an open position and permits a siphoning of oil from sump26 through tube 7 and return line 8 to said reser- V011 FIGS. 3 and 4 reveal a check valve 11 in the oil feed pipe 4 proximate to said oil pump 3. When the machine is in operation, said check valve 11 is in open position thereby allowing the flow of oil there-through but, when the machine is not in operation, said check valve 11 assumes a closed position thereby preventing the flow of oil therethrough. Said check valve 11 (FIG. 3) may be constructed so that when the machine is not in operation a blocking ball 16 gravitationally bears against said check valve 11 thereby blocking and closing said check valve 11, but when the machine is in operation, said ball is lifted against a stopper bar 38 by a specified pressure of oil flowing from oil pump 3 through feed pipe 4, thereby opening said check valve 11 and allowing oil to pass through said check valve 11. In the alternative, said check valve 11 (FIG. 4) may be constructed so that a spring 13 closes said check valve 11 when the machine is not in operation, but when the machine is in operation, said spring 13 is compressed by a specified pressure of oil flowing from oil pump 3 through feed pipe 4 thereby opening said check valve 11 and allowing oil to pass therethrough. FIG. 3 further shows a check valve 31 inserted in tube 7 proximate itslower end 33 to prevent a possible reversal of the siphoned flow from sump chamber 6 through tube 7. Blocking ball 34 and stopper bar 34 perform analagous functions to blocking ball 16 and stopper bar 38 discussed above.

Now, referring to FIGS. 1 and 4, let the oil level in said sump 6, located in the jaw portion of the sewing machine, be denoted by the line xx, the difference in height between said line xx and the highest point of oil tube 7 by H the difference in height between said line x-x and said bearing metal by H the difference in height between said line xx and the oil level of said reservoir 2 by H and the difference between said line x-x and said oil pump 3 by H then the following are illustrative dimensions of the present invention:

5.5 cm (ca.). 6.5 cm (ca.). 6.0 cm. (ca.).

Considering a syphon system comprising tube 7 and oil piping system P, even if a considerable loss of head were to occur within oil piping system P, e.g. the check valves 11 and 12 (FIG. 4) were to fail when the machine was not in operation thereby causing the oil in oil pipe 4 and in return line 8 to drain into said reservoir 2, oil would remain in said oil discharge pipe 7 having a head of H which would cause a siphoning of oil from sump chamber 6 through said oil discharge pipe 7 to said threeway junction 1. Said siphoning to said three-way junction 1 would in turn be adequate to initiate the complete siphoning process of oil from said sump chamber 6 to said reservoir 2 thereby avoiding any damage to the machine by an overflow of excess oil in sump 6.

Also, in the embodiment shown in FIG. 1, where, as a practical matter, an oil pump 3 is employed and its pressure maintained when the machine is not in operation due to the viscosity of the oil, e.g. in an oil pump 3 having a screw shaft, the oil in oil feed pipe 4 would not flow despite the siphoned flow that would be obtained in the tube '7 and return line 8.

Lastly, in the embodiment shown by FIGS. 1, 2 and 3, the reduced pressure obtained in the vicinity of said tip 32 of said nozzle 18 when the machine is in operation results in a siphoned fiow of oil from said sump 6 located in the jaw portion 5 of the machine through said oil discharge pipe 7 to said three-way junction 1, and even if said machine operation were to be stopped, the siphoned flow would not stop or reverse its direction but would be maintained resulting in a withdrawal of oil from said sump 6 located in the jaw portion 5 of the machine to said reservoir 2.

What I claim is:

1. A lubricating system comprising an oil reservoir, a pressure pump positioned to take oil from said reservoir, an oil feed line connecting with the output of said pressure pump, a sump adapted to receive excess oil from the lubricating system and located above the level of said reservoir, said oil feed line having a point located above the level of said sump, a return line connected to said oil feed line at said point and extending to said reservoir, and a tube connecting between said sump and said point of said oil line for withdrawal of excess oil from said sump.

2. Lubrication system in accordance with claim 1, said tube having a check valve therein adjacent said point of said oil line, said check valve being adapted to prevent how of oil from said oil feed line into said tube but to permit flow of oil from said tube to said return line.

3. Lubricating system in accordance with claim 1, said system further including a check valve in said oil feed line permitting flow of oil to said return line when said pump is operating and blocking reverse flow of oil through said feed line when the pump is stopped.

4. Lubrication system in accordance with claim 2, said lubricating system including a further check valve disposed in said oil feed line and operative to permit flow of oil to said return line when said pump is operating and to prevent reverse flow of oil through said feed line when said pump is inoperative.

References Cited in the file of this patent UNITED STATES PATENTS 1,350,729 Kiewicz Aug. 24, 1920 1,661,699 Magnin Mar. 6, 1928 2,386,349 Sauer Oct. 9, 1945 2,502,346 Sauer Mar. 28, 1950 2,837,173 Ciecior June 3, 1958 

